Cod sursa(job #3154976)
Utilizator | Data | 6 octombrie 2023 23:24:55 | |
---|---|---|---|
Problema | Arbori indexati binar | Scor | 20 |
Compilator | cpp-64 | Status | done |
Runda | Arhiva educationala | Marime | 1.59 kb |
#include <fstream>
#include <algorithm>
#include <vector>
using namespace std;
ifstream cin("aib.in");
ofstream cout("aib.out");
int n;
int v[1001], aib[1001];
int sum;
void update (int x,int val)
{
while(x<=n)
{
aib[x]+=val;
x+=x&(-x);
}
}
int prefix(int x)
{
sum=0;
while(x>0)
{
sum+=aib[x];
x-=x&(-x);
}
return sum;
}
int main()
{
int k;
cin>>n>>k;
for(int i=1;i<=n;i++)
{
cin>>v[i];
}
for(int i=1;i<=n;i++)
{
update(i,v[i]);
}
for(int i=1;i<=k;i++)
{
int x,a,b;
cin>>x;
if(x==0)
{
cin>>a>>b;
update(a,b);
}
else if(x==1)
{
cin>>a>>b;
cout<<prefix(b)-prefix(a-1)<<'\n';
}
else
{
cin>>a;
int st=1,dr=n+1,mij;
int y;
while(st<dr)
{
mij=(st+dr)/2;
y=prefix(mij);
if(y==a)
{
break;
}
if(y>a)
{
dr=mij;
}
else
{
st=mij+1;
}
}
if(y==a)
cout<<mij<<'\n';
else
{
cout<<-1<<'\n';
}
}
}
return 0;
}